The required sample size for the study was 177 patients or 59 subjects per group to detect differences greater than or equal 15% in the percentage reduction in excess volume (PREV) between control and experimental groups, if exists; considering differences less than 15% as not clinically significant. It was based on an alpha error of 5% and a power of 90%. We estimated a drop-out rate of 10%. Therefore, 17 patients were added, resulting in a sample size of 194 subjects.